Systems and methods for transducer assemblies

Abstract

Systems and methods for a transducer assembly (700, 1600) are provided. In one example, the transducer assembly includes a flexible circuit (702) and a transducer (600), where the transducer (600) includes a piezoelectric layer (502) and an impedance matching layer (505). The transducer (600) includes a plurality of transducer elements (602) formed via a plurality of diced cutouts (608) positioned between adjacent transducer elements of the plurality of transducer elements (602), where each of the plurality of diced cutouts (608) extends only partially through the impedance matching layer (505).

Description

Technical Field

[0001] Embodiments of the subject matter disclosed herein relate to transducer assemblies, and more particularly to methods of making transducer assemblies. Background Art

[0002] Current ultrasound transducer assemblies are commonly used in applications including non-destructive inspection (NDE) and medical diagnostic imaging, such as ultrasound applications. Ultrasound transducer assemblies typically include an array of ultrasound transducer elements coupled to an array of electronics (eg, a flex circuit).

[0003] Typically, an ultrasonic transducer assembly includes a transducer having hundreds or thousands of individual transducer elements. A piezoelectric transducer (e.g., a lead zirconate titanate transducer) is a widely used type of ultrasonic transducer. A piezoelectric transducer typically includes a piezoelectric material that is capable of changing physical dimensions when subjected to electrical or mechanical stress. In addition, a piezoelectric transducer may include layers of impedance matching material and layers of impedance dematching material. A flexible circuit may be electrically coupled to the transducer elements to provide electrical control of the transducer for beamforming, signal amplification, control functions, signal processing, and the like.

[0004] Large arrays of transducer elements can be formed by cutting the transducer into rows and / or columns. An array of transducer elements can be one-dimensional (1D) (e.g., a linear array or row of transducer elements) for two-dimensional (2D) imaging. Similarly, an array can be 2D for three-dimensional (3D) imaging (e.g., volumetric imaging). Each transducer assembly includes a subarray of transducer elements and a flexible circuit coupled to the transducer elements. Summary of the invention

[0005] In one embodiment, the transducer assembly includes a flexible circuit and a transducer, wherein the transducer includes a piezoelectric layer and an impedance matching layer. The transducer includes a plurality of transducer elements formed via a plurality of dicing cuts positioned between adjacent transducer elements of the plurality of transducer elements, wherein each of the plurality of dicing cuts extends only partially through the impedance matching layer.

[0006] It should be understood that the above brief description is provided to introduce in a simplified form selected concepts that are further described in the detailed description. It is not meant to identify key features or essential features of the claimed subject matter, the scope of which is uniquely defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present disclosure will be better understood by reading the following description of non-limiting embodiments with reference to the accompanying drawings, in which:

[0008] Figure 1 shows a schematic diagram of an ultrasound imaging system;

[0009] Figure 2 A composite wafer including dicing cuts oriented in two orthogonal directions is shown;

[0010] Figure 3 shows the transducer is divided into Figure 2 Composite wafer;

[0011] Figure 4 Shows Figure 3 transducers and flexible circuits;

[0012] Figure 5 shows a cross-sectional view of an exemplary transducer prior to dicing;

[0013] Figure 6 shows a first cross-sectional view of an exemplary transducer after dicing;

[0014] Figure 7 Shown include Figure 6 a cross-sectional view of an exemplary transducer assembly of a diced transducer and a flexible circuit including a ground restoration region;

[0015] Figure 8 A two-dimensional transducer including a ground restoration region is shown;

[0016] Fig. 9 A method for manufacturing a one-dimensional transducer probe is shown;

[0017] Fig.10 A method for manufacturing a two-dimensional transducer probe is shown;

[0018] Fig.11 A composite wafer including a piezoelectric layer is shown;

[0019] Fig.12 A composite wafer including dicing cuts oriented in a single direction is shown;

[0020] Fig.13 shows a second cross-sectional view of the exemplary transducer after dicing;

[0021] Fig.14 A first one-dimensional transducer including a ground restoration region is shown;

[0022] Fig.15 showing a second one-dimensional transducer including a ground restoration region; and

[0023] Fig.16 A cross-sectional view of another exemplary transducer assembly including a diced transducer and a flex circuit including a ground restoration region is shown. DETAILED DESCRIPTION

[0024] Embodiments of the subject matter disclosed herein and of the specification relate to transducer assemblies and methods and systems for manufacturing transducer assemblies. Typically, in the manufacture of an ultrasonic (e.g., transducer) probe, the transducer is coupled to a flexible circuit before being cut into transducer elements. Thus, each transducer is individually diced as part of a transducer assembly. In this way, the dicing equipment footprint can be increased compared to methods that dice multiple transducers together. In addition, conductive material is typically added to the transducer assembly as a continuous film or layer after dicing occurs to ensure ground recovery of the transducer assembly. The deposition of additional layers or films increases the manufacturing complexity and material cost of each ultrasonic probe.

[0025] Therefore, embodiments of transducer assemblies for manufacturing ultrasound probes that allow multiple transducers to be diced together are provided herein, wherein each transducer assembly includes a conductive material for ground recovery. A composite wafer may be diced and then divided into individual transducers, wherein each transducer is configured for an ultrasound probe. By dicing the transducers together as part of a composite wafer, the dicing time may be reduced by reducing the number of times the transducers are loaded and / or unloaded from the dicing equipment. In addition, at least a portion of the impedance matching layer of each transducer may not be diced, thereby producing a continuous layer that extends completely across the transducer. Therefore, the impedance matching layer of the transducer may provide mechanical support and may include a conductive material for ground recovery of the transducer. In this way, an additional conductive layer / film may not be deposited on each transducer, thereby reducing manufacturing costs and complexity.

[0026] The transducer assembly can be used for diagnostic imaging and can be integrated into imaging systems such as Figure 1 The ultrasonic imaging system shown in FIG. 1 may include a transducer taken from a composite wafer and bonded to a flexible circuit (e.g., an electronic device array). The composite wafer may include an impedance matching layer, an impedance dematching layer, and a piezoelectric layer, such as Fig.11 exemplified. exist Figure 2 and Fig.12 , which in some examples includes hundreds or thousands of transducer elements, is shown in FIG. Figure 2 illustrates a composite wafer that has been diced along two orthogonal directions, and Fig.12 The composite wafer is illustrated as being diced in a single direction. The composite wafer may include one or more transducers, wherein each transducer includes an array of diced transducer elements. Each transducer may be removed from the composite wafer (e.g., Figure 3 ) and bonded to a flexible circuit (as Figure 4 shown). Figure 5The transducer is illustrated prior to dicing, which may include an impedance matching layer, a piezoelectric layer, and an impedance de-matching layer. The dicing cut may extend into the transducer, completely through the piezoelectric layer and the impedance de-matching layer, and only partially through the impedance matching layer, such as Figure 6 and Fig.13 As shown. The dicing cuts can create individual transducer elements, wherein each transducer element is separated from adjacent transducer elements by one or more of the dicing cuts. Thus, in some examples, each transducer element can include an impedance dematching layer positioned below the piezoelectric layer. However, in other examples, such as Fig.16 As illustrated, the impedance dematching layer below the piezoelectric layer may be omitted. Each of the transducer elements may be aligned with and bonded to a contact pad of a flexible circuit (eg, a printed circuit board), such as Figure 7 Alignment of the transducer elements with the contact pads may be facilitated by pick-and-place equipment to ensure proper electrical connection. The transducer elements may be arranged in a central section of the transducer, and both ends of the transducer may include ground recovery regions, such as Figure 8 , Fig.14 and Fig.15 As shown. The ground recovery area of ​​the transducer can be aligned with the ground signal connection of the flexible circuit so that the transducer assembly is grounded. In addition, the ground recovery area can be oriented so that the desired imaging footprint is achieved. Fig. 9 and Fig.10 A method for manufacturing a one-dimensional transducer assembly and a method for manufacturing a two-dimensional transducer assembly are illustrated in FIG.

[0027] Figure 1 A schematic diagram of an ultrasound imaging system 100 according to one embodiment of the present disclosure is shown. The ultrasound imaging system 100 includes a transmit beamformer 101 and a transmitter 102, which drives an element (e.g., a transducer element) 104 within a transducer assembly (referred to herein as a probe 106) to transmit a pulsed ultrasound signal (referred to herein as a transmit pulse) into a body (not shown). According to an embodiment, the probe 106 may be a one-dimensional transducer assembly probe. However, in some embodiments, the probe 106 may be a two-dimensional matrix transducer assembly probe. As further explained below, the transducer element 104 may be made of a piezoelectric material. When a voltage is applied to a piezoelectric crystal, the crystal physically expands and contracts, thereby transmitting an ultrasonic spherical wave. In this way, the transducer element 104 can convert an electronic transmit signal into an acoustic transmit beam.

[0028] After the transducer elements 104 of the probe 106 transmit pulsed ultrasound signals into the body (of the patient), the pulsed ultrasound signals are backscattered from structures inside the body (such as blood cells or muscle tissue) to generate echoes that return to the transducer elements 104. The echoes are converted into electrical signals or ultrasound data by the transducer elements 104, and the electrical signals are received by the receiver 108. The electrical signals representing the received echoes pass through the receive beamformer 110 that outputs ultrasound data. Additionally, the transducer elements 104 may generate one or more ultrasound pulses based on the received echoes to form one or more transmit beams.

[0029] According to some embodiments, the probe 106 may contain electronic circuits to perform all or part of the transmit beamforming and / or receive beamforming. For example, all or part of the transmit beamformer 101, the transmitter 102, the receiver 108, and the receive beamformer 110 may be located within the probe 106. In the present disclosure, the term "scan" may also be used to refer to the process of transmitting and receiving ultrasound signals to collect data. In the present disclosure, the term "data" may be used to refer to one or more data sets collected by the ultrasound imaging system. In one embodiment, the data collected via the ultrasound imaging system 100 can be used to train a machine learning model. The user interface 115 can be used to control the operation of the ultrasound imaging system 100, including controlling the input of patient data (e.g., patient medical history), changing scanning or display parameters, starting a probe repolarization sequence, etc. The user interface 115 may include one or more of the following items: a rotating element, a mouse, a keyboard, a trackball, a hard key linked to a specific action, a soft key that can be configured to control different functions, and a graphical user interface displayed on a display device 118.

[0030] The ultrasound imaging system 100 also includes a processor 116 that controls the transmit beamformer 101, the transmitter 102, the receiver 108, and the receive beamformer 110. The processor 116 is in electronic communication (e.g., communicatively connected) with the probe 106. For the purposes of this disclosure, the term "electronic communication" may be defined as including both wired communication and wireless communication. The processor 116 may control the probe 106 to acquire data according to instructions stored in the processor's memory and / or the memory 120. The processor 116 controls which of the transducer elements 104 are active and the shape of the beam emitted from the probe 106. The processor 116 also communicates electronically with the display device 118, and the processor 116 may process data (e.g., ultrasound data) into an image for display on the display device 118. According to an embodiment, the processor 116 may include a central processing unit (CPU). According to other embodiments, the processor 116 may include other electronic components capable of performing processing functions, such as a digital signal processor, a field programmable gate array (FPGA), or a graphics board. According to other embodiments, the processor 116 may include a plurality of electronic components capable of performing processing functions. For example, the processor 116 may include two or more electronic components selected from a list of electronic components, including: a central processing unit, a digital signal processor, a field programmable gate array, and a graphics board. According to another embodiment, the processor 116 may also include a composite demodulator (not shown) that demodulates the RF data and generates raw data. In another embodiment, the demodulation may be performed earlier in the processing chain. The processor 116 is adapted to perform one or more processing operations according to a plurality of optional ultrasound modalities on the data. In one example, the data may be processed in real time during a scanning session because the echo signals are received by the receiver 108 and transmitted to the processor 116. For the purposes of this disclosure, the term "real time" is defined as including a program executed without any intentional delay. For example, an embodiment may acquire images at a real-time rate of 7 frames / second to 20 frames / second. The ultrasound imaging system 100 may acquire 2D data of one or more planes at a significantly faster rate. However, it should be understood that the real-time frame rate may depend on the length of time it takes to acquire each frame of data for display. Therefore, when a relatively large amount of data is acquired, the real-time frame rate may be slower. Thus, some embodiments may have real-time frame rates significantly faster than 20 frames / second, while other embodiments may have real-time frame rates less than 7 frames / second. Data may be temporarily stored in a buffer (not shown) during a scanning session and processed in less than real-time in real-time or off-line operations. Some embodiments of the present invention may include multiple processors (not shown) to handle processing tasks handled by processor 116 according to the exemplary embodiments described above.For example, a first processor may be utilized to demodulate and extract the RF signal prior to displaying an image, while a second processor may be utilized to further process the data (eg, by augmenting the data as further described herein). It should be appreciated that other embodiments may utilize different processor arrangements.

[0031] The ultrasound imaging system 100 can continuously acquire data at a frame rate of, for example, 10 Hz to 30 Hz (e.g., 10 to 30 frames per second). The image generated based on the data can be refreshed at a similar frame rate on the display device 118. Other embodiments can acquire and display data at different rates. For example, depending on the size of the frame and the intended application, some embodiments can acquire data at a frame rate less than 10 Hz or greater than 30 Hz. A memory 120 is included to store processed frames of the acquired data. In an exemplary embodiment, the memory 120 has sufficient capacity to store at least a few seconds of ultrasound data frames. The data frames are stored in a manner that is easy to retrieve according to their acquisition order or time. The memory 120 may include any known data storage medium.

[0032] In various embodiments of the present invention, the processor 116 may process data in different mode-related modules (e.g., B-mode, color Doppler, M-mode, color M-mode, spectral Doppler, elastic imaging, TVI, strain, strain rate, etc.) to form 2D or 3D data. For example, one or more modules may generate B-mode, color Doppler, M-mode, color M-mode, spectral Doppler, elastic imaging, TVI, strain, strain rate, and combinations thereof, etc. As an example, one or more modules may process color Doppler data, which may include traditional color blood flow Doppler, power Doppler, HD flow, etc. The image lines and / or frames are stored in the memory and may include timing information indicating the time when the image lines and / or frames are stored in the memory. These modules may include, for example, a scan conversion module that performs a scan conversion operation to convert the acquired image from beam space coordinates to display space coordinates. A video processor module may be provided that reads the acquired image from the memory and displays the image in real time while a procedure (e.g., ultrasound imaging) is performed on the patient. The video processor module may include a separate image memory, and the ultrasound image may be written to the image memory for reading and display by the display device 118 .

[0033] In various embodiments of the present disclosure, one or more components of the ultrasound imaging system 100 may be included in a portable handheld ultrasound imaging device. For example, the display device 118 and the user interface 115 may be integrated into the external surface of the handheld ultrasound imaging device, which may further contain a processor 116 and a memory 120. The probe 106 may include a handheld probe that electronically communicates with the handheld ultrasound imaging device to collect raw ultrasound data. The transmit beamformer 101, the transmitter 102, the receiver 108, and the receive beamformer 110 may be included in the same or different parts of the ultrasound imaging system 100. For example, the transmit beamformer 101, the transmitter 102, the receiver 108, and the receive beamformer 110 may be included in a handheld ultrasound imaging device, a probe, and a combination thereof.

[0034] After performing a two-dimensional ultrasound scan, a data block including scan lines and their samples is generated. After applying the back-end filter, a process called scan conversion is performed to transform the two-dimensional data block into a displayable bitmap image with additional scanning information (such as depth, the angle of each scan line, etc.). During scan conversion, interpolation techniques are applied to fill in the missing holes (e.g., pixels) in the resulting image. These missing pixels occur because each element of the two-dimensional block typically covers many pixels in the resulting image. For example, in current ultrasound imaging systems, bicubic interpolation is applied, which utilizes adjacent elements of the two-dimensional block. Therefore, if the two-dimensional block is relatively small compared to the size of the bitmap image, the scan-converted image will include areas of poor or low resolution, especially for areas with greater depth.

[0035] Figure 2 The composite wafer 200 is shown having been diced. Figures 2 to 8 and Figures 11 to 16 A coordinate system for orienting the view is included. In one example, the z-axis can be a vertical axis (e.g., parallel to the gravity axis), the y-axis can be a longitudinal axis (e.g., a horizontal axis), and / or the z-axis can be a transverse axis. However, in other examples, the axes can have other orientations.

[0036] The composite wafer 200 may include a piezoelectric layer, an impedance matching layer, and an impedance dematching layer 201 (in Figure 2 In the illustrated view, the piezoelectric layer and the impedance matching layer are positioned below the impedance dematching layer and thus Figure 2 The piezoelectric layer may be positioned intermediate at least a portion of the impedance matching layer and at least a portion of the impedance de-matching layer 201 relative to the z-axis.

[0037] Steering Fig.11, illustrating the positioning of the piezoelectric layer of the composite wafer 200. The positioning of the piezoelectric layer within the composite wafer 200 is represented by a first piezoelectric segment 250 and a second piezoelectric segment 252. The first piezoelectric segment 250 and the second piezoelectric segment 252 can each extend across the length of the composite wafer 200 relative to the x-axis. A portion 254 of the conductive grounding material can be positioned between the first piezoelectric segment 250 and the second piezoelectric segment 252 relative to the y-axis. In addition, a portion 256 of the conductive grounding material can be positioned between the first piezoelectric segment 250 and a first edge 258 of the composite wafer 200. Similarly, a portion 260 of the conductive grounding material can be positioned between the second piezoelectric segment 252 and a second edge 262 of the composite wafer 200, wherein the second edge 262 is opposite the first edge 258 relative to the y-axis.

[0038] The composite wafer 200 is configured such that the composite wafer can be divided into one or more transducers, each of which can be included in an ultrasound probe (eg, Figure 1 For example, Figure 2 As illustrated, the composite wafer 200 may be cut (e.g., via a saw, a laser, etc.) into a plurality of transducers. In some examples, the dicing of the composite wafer 200 may be performed using a standard dicing saw or via laser dicing. In other examples, deep reactive ion or other semiconductor type etching may be used with an intermediate masking step. As a result of dicing, the composite wafer 200 may include a plurality of dicing cuts 208. The composite wafer 200 may be diced such that the dicing cuts 208 extend in two orthogonal directions. In this way, the composite wafer 200 may be divided into transducers for a one-dimensional ultrasound probe configured for two-dimensional imaging.

[0039] The dicing cuts 208 may include dicing cuts parallel to the x-axis (such as the second dicing cuts 210) and dicing cuts parallel to the y-axis (such as the third dicing cuts 212). Therefore, the second dicing cuts 210 and the third dicing cuts 212 may be oriented orthogonally to each other. The dicing cuts 208 divide a portion of the composite wafer 200 into a plurality of transducer elements 202, such as a first transducer element 204 and a second transducer element 206. Each of the transducer elements 202 may include a portion of an impedance dematching layer 201 stacked on top of a portion of the piezoelectric layer relative to the z-axis. The dicing cuts 208 may separate the transducer elements 202 from adjacent transducer elements. In the illustrated example, each of the transducer elements 202 may have a square or rectangular cross-section parallel to the xy plane. In some examples, the composite wafer 200 may be diced into hundreds or thousands of transducer elements.

[0040] The dicing cut 208 may also separate the transducer element 202 from a ground restoration region of the composite wafer, such as the first ground restoration region 216 and the second ground restoration region 218. The ground restoration region may correspond to a portion of the composite wafer 200 that does not have a piezoelectric layer, such as Fig.11 254, 256 and / or 260. For example, Figure 2 As illustrated, the first ground restoration region 216 and the second ground restoration region 218 may be respectively located along one edge of the composite wafer 200 and at the center of the composite wafer relative to the y-axis, and may each extend completely across the composite wafer parallel to the x-axis. Each of the ground restoration regions may include a conductive material to facilitate grounding of the transducer element 202.

[0041] The composite wafer 200 may be diced starting from the impedance dematching layer 201 of the composite wafer. Thus, the dicing cut 208 may extend completely through the impedance dematching layer 201 relative to the z-axis. In addition, the dicing cut 208 may extend completely through the piezoelectric layer relative to the z-axis. Thus, the dicing cut 208 may extend deep enough to separate adjacent transducer elements from each other, wherein each transducer element includes a portion of the piezoelectric layer stacked on top of a portion of the impedance dematching layer 201 relative to the z-axis. However, in some examples, the dicing cut 208 may only partially extend through the impedance matching layer, and in other examples may not extend into the impedance matching layer at all. Thus, the dicing cut 208 does not extend through the entire impedance matching layer, and may terminate within the impedance matching layer or before reaching the impedance matching layer. In this way, the impedance matching layer may provide common mechanical support for the transducer element 202. In addition, the impedance matching layer may include a conductive material for ground recovery of the transducer element 202. Therefore, after dicing, conductive films and / or conductive layers may not be deposited onto composite wafer 200 , thereby reducing the number of manufacturing steps (eg, manufacturing complexity).

[0042] Figure 3 A composite wafer 200 including a plurality of transducers 300 is schematically shown. In the illustrated example, the plurality of transducers 300 (e.g., the composite wafer 200) includes six transducers, such as a first transducer 302 and a second transducer 304. In other examples, the plurality of transducers 300 may include more or less than six transducers. Each transducer includes a portion of a transducer element 202, wherein adjacent transducer elements are separated by a dicing cut 208. In addition, each transducer includes a portion of one or more of the ground restoration regions, such as Figure 2 A portion of the second ground restoration region 218 is formed.

[0043] like Figure 3As shown, first transducer 302 may be removed from the remainder of composite wafer 200 (such as second transducer 304). One or more deep cut block cuts of composite wafer 200 may extend completely through the composite wafer relative to the z-axis, such that the deep cut block cuts may separate the composite wafer into transducers 300. For example, first deep cut block cut 306 and second deep cut block cut 308 may extend completely through composite wafer 200 relative to the z-axis and may separate first transducer 302 from the remainder of the composite wafer. The separation between first transducer 302 and the remainder of the composite wafer (such as second transducer 304) created by first deep cut block cut 306 and second deep cut block cut 308 allows the first transducer 302 to be removed from the composite wafer. Once removed, first transducer 302 may be coupled to a flexible circuit, such as Figure 4 exemplified.

[0044] Figure 4 The diagram includes a circuit coupled to a flexible circuit 402. Figure 3 The first transducer 302 of the embodiment of the present invention is a transducer assembly 400 of the first transducer 302. The flexible circuit 402 can be an array of electronic devices configured to receive electrical signals from the first transducer 302. In some examples, the flexible circuit 402 can be a printed circuit board (PCB). The first transducer 302 can be aligned with the flexible circuit 402 by pick and place equipment. Therefore, the individual transducer elements of the first transducer 302 can be properly aligned with the contact pads of the flexible circuit 402. In some examples, the first transducer 302 can be diced again after being attached to the flexible circuit 402 to enhance directivity and reduce acoustic crosstalk.

[0045] Figure 5 A cross-sectional view of an exemplary transducer 500 is shown. Transducer 500 includes a piezoelectric layer 502. In some examples, piezoelectric layer 502 includes single crystal lead zirconate titanate (PZT).

[0046] The transducer 500 also includes an impedance matching layer 505. The acoustic impedance of the impedance matching layer 505 may be between the acoustic impedance of water and the acoustic impedance of the piezoelectric layer 502. Thus, the impedance matching layer 505 may provide an acoustic impedance gradient for allowing sound waves to smoothly penetrate body tissue and return to the piezoelectric layer 502 for detection. Additionally, in some examples, the impedance matching layer 505 may include ceramics, silicon, flexible organic polymers, metal-filled graphite, ceramic powder-filled epoxy, glass, and glass ceramics. Furthermore, the impedance matching layer 505 may include a first sublayer 504 and a second sublayer 506. With respect to the z-axis, the second sublayer 506 may be positioned on top of the first sublayer 504, and at least a portion of the first sublayer may be positioned on top of the piezoelectric layer 502. In some examples, the second sublayer 506 may be omitted from the transducer 500, and thus the impedance matching layer 505 may include a single layer (e.g., the first sublayer 504). The first sub-layer 504 and / or the second sub-layer 506 may include a conductive material for ground restoration of the transducer 500 .

[0047] Transducer 500 also includes an impedance dematching layer 508, a first end segment 510, and a second end segment 512. Dematching layer 508 is positioned in the middle of the two end segments relative to the y-axis. Therefore, piezoelectric layer 502 can be positioned in the middle of first end segment 510 and second end segment 512 relative to the y-axis. In addition, piezoelectric layer 502 can be positioned above a portion of impedance dematching layer 508 relative to the z-axis.

[0048] In some examples, the impedance dematching layer 508 may include a dense, high modulus metal (such as molybdenum or tungsten) and / or a high density ceramic (such as tungsten carbide). The acoustic impedance of the impedance dematching layer 508 may be greater than the acoustic impedance of the piezoelectric layer 502. Thus, the impedance dematching layer 508 may reduce and / or prevent the back-emitted acoustic waves from echoing (e.g., ringing back) into the piezoelectric layer 502 for detection. The first end segment 510 and the second end segment 512 may be composed of a conductive material, which is a different material than the impedance dematching layer, at least in some examples. In addition, although Figure 5 The first end section 510 and the second end section 512 are shown extending from the impedance matching layer to the bottom of the transducer, but in some examples, the impedance dematching layer 508 may extend across the entire bottom of the transducer, and the first end section 510 and the second end section 512 may extend from the impedance matching layer to the impedance dematching layer. Because the first end section and the second end section may facilitate ground restoration, the first end section and the second end section may also be referred to herein as a first ground restoration region and a second ground restoration region.

[0049] Figure 6 A cross-sectional view of an exemplary transducer 600 after dicing is shown. Figure 6 The cross-sectional view shown is along Figure 3 The transducer 600 may be Figure 3 The transducer 600 includes a non-limiting example of a first transducer 302. Figure 5 600, a piezoelectric layer 502, an impedance matching layer 505, an impedance dematching layer 508, a first end segment 510 (e.g., a grounded conductive material) and a second end segment 512, and a plurality of diced cuts 608. The piezoelectric layer 502 may be positioned relative to the y-axis between the first end segment 510 and the second end segment 512. Thus, the piezoelectric layer 502 may not fully extend across the transducer 600 relative to the y-axis.

[0050] A plurality of diced cuts 608 may extend from a bottom side 620 of the transducer into the transducer 600. The plurality of diced cuts 608 may be Figure 2 608 can extend parallel to the z-axis all the way through the impedance dematching layer 508 and the piezoelectric layer 502. In this manner, the diced cut 608 can separate adjacent transducer elements of the transducer element 602. For example, the diced cut 618 can separate the first transducer element 614 from the second transducer element 616. Similarly, a diced cut orthogonal to the diced cut 618 can separate the first transducer element 614 and the second transducer element 616 from adjacent transducer elements located at different points along the x-axis. The transducer element 602 can be Figure 2 Non-limiting examples of transducer elements 202 .

[0051] The diced cut 608 may extend partially through the impedance matching layer 505 relative to the z-axis. In the illustrated example, the diced cut 608 may extend partially into the first sub-layer 504 and may not extend into the second sub-layer 506. Thus, a portion of the impedance matching layer 505 may remain continuous and may provide mechanical support for the transducer elements of the transducer 600. For example, the bottom surface of the first sub-layer 504 of the impedance matching layer (e.g., which is in face-sharing contact with the piezoelectric layer 502 or has the impedance matching layer adhesively coupled to the piezoelectric layer) may be interrupted along the y-axis (and the x-axis) by the diced cut 608, while the top surface of the first sub-layer 504 of the impedance matching layer 505 (e.g., which is in face-sharing contact with the second sub-layer 506 or faces the environment when the second sub-layer is omitted) may extend continuously along both the y-axis and the x-axis without being interrupted by the diced cut 608. In addition, the impedance matching layer 505 may provide ground restoration for the transducer 600. By omitting dicing cut 608 from at least a portion of impedance matching layer 505, deposition of additional layers or films for providing mechanical support and / or ground recovery may be omitted from the manufacturing method of transducer 600. Thus, by dicing transducer 600 from bottom side 620, manufacturing complexity and the amount of manufacturing material may be reduced.

[0052] Fig.13 Another cross-sectional view of example transducer 600 is shown after dicing. Fig.13 The cross-sectional view shown is along Figure 3 The cutting plane B-B' is intercepted. Fig.13 The illustrated transducer 600 includes Figure 5 The piezoelectric layer 502, the impedance matching layer 505 and the impedance de-matching layer 508 of the transducer 500 and Figure 6 The piezoelectric layer 502 may extend completely across the transducer 600 relative to the x-axis.

[0053] A plurality of dicing cuts 608 can extend from a bottom side 620 of the transducer into the transducer 600. The dicing cuts 608 can extend parallel to the z-axis all the way through the impedance dematching layer 508 and the piezoelectric layer 502. In this manner, the dicing cuts 608 can separate the transducer elements 602 from adjacent transducer elements. For example, the dicing cuts 1302 can separate the first transducer element 1304 from the second transducer element 1306. Similarly, dicing cuts orthogonal to the dicing cuts 1302 can separate the first transducer element 1304 and the second transducer element 1306 from adjacent transducer elements located at different points along the y-axis.

[0054] Figure 7 700 includes a transducer 600 and a flexible circuit 702. The flexible circuit 702 can be positioned below the transducer 600 relative to the z-axis. In addition, the flexible circuit 702 can be aligned with the bottom surface of the impedance dematching layer 508 of the transducer 600 (e.g., Figure 6 702). Thus, the flexible circuit 702 can make face-sharing contact with each of the transducer elements 602, such as the first transducer element 614. In this way, the transducer elements 602 can be electrically connected to element signal connections of the flexible circuit 702, such as the first element signal connection 712. The transducer elements 602 can be aligned with the contact pads of the flexible circuit 702 via pick-and-place equipment to ensure proper alignment and reliable signal connection. In some examples, once aligned, the transducer elements 602 can be bonded to the flexible circuit 702 via epoxy (e.g., glue), anisotropic conductive particles (e.g., ACP), or anisotropic conductive film (e.g., ACF).

[0055] The flexible circuit 702 may include ground restoration regions, such as a first ground restoration region 704 and a second ground restoration region 706. Each ground restoration region may be positioned below an end segment of the transducer 600. For example, the first ground restoration region 704 is positioned below the first end segment 510, and the second ground restoration region 706 is positioned below the second end segment 512. Thus, the ground restoration region may be in electrical communication with the conductive material in the end segment of the transducer 600. The ground restoration region may be connected to a ground signal connection, such as a ground signal connection 708, which facilitates ground restoration for the transducer 600. Thus, ground restoration of the transducer 600 may be performed via one or more conductive materials in the impedance matching layer 505 and / or the first and second end segments, and the impedance dematching layer 508, as well as the ground restoration region and the ground signal connection. In this way, the transducer 600 may be grounded without depositing additional conductive layers or films onto the transducer and manufacturing complexity may be reduced.

[0056] Fig.16 The device includes a transducer 1601 and Figure 7 1 is a cross-sectional view of another exemplary transducer assembly 1600 of a flexible circuit 702. Transducer 1601 can be similar to transducer 600, except that transducer 1601 can lack an impedance dematching layer. Transducer 1601 includes a piezoelectric layer 1602. In some examples, piezoelectric layer 1602 includes single crystal lead zirconate titanate (PZT).

[0057] Transducer 1601 also includes an impedance matching layer 1605, which includes a first sublayer 1604 and a second sublayer 1606. Relative to the z-axis, the second sublayer 1606 can be positioned on top of the first sublayer 1604, and at least a portion of the first sublayer can be positioned on top of the piezoelectric layer 1602. In some examples, the second sublayer 1606 can be omitted from the transducer 1601, and thus the impedance matching layer 1605 can include a single layer (e.g., the first sublayer 1604). The first sublayer 1604 and / or the second sublayer 1606 may include a conductive material for ground recovery of the transducer 1601.

[0058] Transducer 1601 also includes a first end segment 1610 and a second end segment 1612. Each of first end segment 1610 and second end segment 1612 includes a grounded conductive material. Piezoelectric layer 1602 can be positioned intermediate first end segment 1610 and second end segment 1612 relative to the y-axis. Thus, piezoelectric layer 1602 can not fully extend across transducer 1601 relative to the y-axis. Additionally, piezoelectric layer 1602 can be positioned above a portion of flexible circuit 702 relative to the z-axis. A bottom surface of piezoelectric layer 1602 can be in surface-sharing contact (e.g., direct contact) with a top surface of flexible circuit 702. First end segment 1610 and second end segment 1612 can be comprised of a conductive material, as described above relative to Figure 5 Explained.

[0059] Transducer 1601 includes a plurality of diced cuts 1608. The plurality of diced cuts 1608 may extend from the bottom side of the transducer into transducer 1601. The plurality of diced cuts 1608 may be Figure 2 16. The dicing cuts 1608 may extend parallel to the z-axis all the way through the piezoelectric layer 1602. In this manner, the dicing cuts 1608 may separate a transducer element from an adjacent transducer element, wherein each transducer element includes a portion of the piezoelectric layer 1602. For example, one of the dicing cuts 1608 may separate the first transducer element 1614 from the second transducer element 1616. Similarly, one of the dicing cuts 1608 may separate the first transducer element 1614 and the second transducer element 1616 from adjacent transducer elements that are positioned at different points along the x-axis.

[0060] The diced cut 1608 may extend partially through the impedance matching layer 1605 relative to the z-axis. In the illustrated example, the diced cut 1608 may extend partially into the first sub-layer 1604 and may not extend into the second sub-layer 1606. Thus, a portion of the impedance matching layer 1605 may remain continuous and may provide mechanical support for the transducer elements of the transducer 1601. For example, the bottom surface of the first sub-layer 1604 of the impedance matching layer (e.g., which is in face-sharing contact with the piezoelectric layer 1602 or has the impedance matching layer adhesively coupled to the piezoelectric layer) may be interrupted along the y-axis (and the x-axis) by the diced cut 1608, while the top surface of the first sub-layer 1604 of the impedance matching layer 1605 (e.g., which is in face-sharing contact with the second sub-layer 1606 or faces the environment when the second sub-layer is omitted) may extend continuously along both the y-axis and the x-axis without being interrupted by the diced cut 1608. Additionally, impedance matching layer 1605 may provide ground restoration for transducer 1601. By configuring dicing cut 1608 such that the dicing cut terminates within first sublayer 1604, deposition of additional layers or films for providing mechanical support and / or ground restoration may be omitted from the manufacturing process of transducer 1601. Thus, by dicing transducer 1601 from the bottom side (e.g., first through piezoelectric layer 1602), manufacturing complexity and the amount of manufacturing material may be reduced.

[0061] The flexible circuit 702 can be positioned below the transducer 1601 relative to the z-axis. In addition, the flexible circuit 702 can make surface-sharing contact (e.g., direct contact) with the bottom surface of the piezoelectric layer 1602 of the transducer 1601. Thus, the flexible circuit 702 can make surface-sharing contact with each of the transducer elements (such as the first transducer element 1614). In this way, the transducer elements can be electrically connected to the element signal connections of the flexible circuit 702, such as the first element signal connection 712. The transducer elements can be aligned with the contact pads of the flexible circuit 702 via pick-and-place equipment to ensure proper alignment and reliable signal connection. In some examples, once aligned, the transducer elements can be bonded to the flexible circuit 702 via epoxy (e.g., glue), anisotropic conductive particles (e.g., ACP), or anisotropic conductive film (e.g., ACF).

[0062] The flexible circuit 702 may include ground recovery regions, such as a first ground recovery region 704 and a second ground recovery region 706. Each ground recovery region may be positioned below an end segment of the transducer 1601. For example, the first ground recovery region 704 is positioned below the first end segment 1610, and the second ground recovery region 706 is positioned below the second end segment 1612. Thus, the ground recovery region may be in electrical communication with the conductive material in the end segment of the transducer 1601. The ground recovery region may be connected to a ground signal connection, such as a ground signal connection 708, which facilitates ground recovery for the transducer 1601. Thus, ground recovery of the transducer 1601 may be performed via the impedance matching layer 1605, one or more conductive materials in the first end segment 1610 and / or the second end segment 1612, and the ground recovery region and the ground signal connection. In this way, the transducer 1601 may be grounded without depositing additional conductive layers or films onto the transducer and manufacturing complexity may be reduced.

[0063] Figure 8 Transducer 800 is shown including horizontal diced cutouts 802 and vertical diced cutouts 804. Transducer 800 may be Figure 6 A non-limiting example of a transducer 600 of FIG. 800 has an impedance dematching layer, a piezoelectric layer, and an impedance matching layer stacked along the z-axis. Transducer 800 is an example of a transducer of a two-dimensional transducer probe (e.g., an ultrasound probe). Therefore, transducer 800 can be used for three-dimensional (e.g., volume) imaging.

[0064] The horizontal diced cut 802 is orthogonal to the vertical diced cut 804, wherein the horizontal diced cut is parallel to the y-axis and the vertical diced cut is parallel to the x-axis. In addition, the horizontal diced cut 802 may extend completely across the transducer 800 relative to the y-axis, and the vertical diced cut 804 may extend completely across the transducer relative to the x-axis. The horizontal diced cut 802 may intersect the vertical diced cut 804 at a 90 degree angle. The horizontal diced cut 802 and the vertical diced cut 804 may be Figure 2 800 and thus can separate adjacent transducer elements of the transducer 800. In addition, the horizontal dicing cut 802 and the vertical dicing cut 804 can extend only partially into the transducer 800 relative to the z-axis. For example, the transducer 800 can include an impedance matching layer into which the dicing cut does not extend.

[0065] In the illustrated example, the transducer 800 includes a first end region 806 and a second end region 808, wherein the second end region is positioned opposite the first end region relative to the y-axis. In addition, the transducer 800 includes a center region 810, wherein the center region is positioned in the middle of the first end region 806 and the second end region 808. The center region 810 includes both the horizontal dicing cut 802 and the vertical dicing cut 804, while the first end region 806 and the second end region 808 may only include the horizontal dicing cut 802. Therefore, the center region 810 may include the transducer elements of the transducer 800, while the first end region 806 and the second end region 808 may not include the transducer elements.

[0066] The first ground restoration region 812 is positioned in the first end region 806, and the second ground restoration region 814 is positioned in the second end region 808. The first ground restoration region 812 and the second ground restoration region 814 can facilitate ground restoration of the transducer 800. For example, ground restoration can be achieved through electrical communication between continuous layers of the transducer 800 (e.g., layers through which the horizontal dicing cuts 802 and the vertical dicing cuts 804 do not extend) and the first ground restoration region 812 and the second ground restoration region 814. In addition, the first ground restoration region 812 and the second ground restoration region 814 can be connected to a flexible circuit (e.g., Figure 7 The flexible circuit 702 is electrically connected.

[0067] One or more continuous conductive layers (eg, impedance matching layers) of transducer 800 allow first ground restoration region 812 and second ground restoration region 814 to be positioned differently depending on the desired utilization of the transducer. For example, in some examples, Figure 8 The locations of the first ground restoration region 812 and the second ground restoration region 814 illustrated in FIG. 8 may be beneficial for a two-dimensional transducer probe (e.g., for volumetric imaging). In other examples, such as when the transducer 800 may be used for a one-dimensional probe (e.g., for two-dimensional imaging), it may be beneficial to position the ground restoration regions in a manner that increases the imaging footprint parallel to a desired axis (e.g., the y-axis).

[0068] In some examples, such as Fig.12 As illustrated, composite wafer 1200 may be diced such that dicing cuts 1202 extend parallel to a single direction. For example, dicing cuts 1202 (such as first dicing cut 1204) may be parallel to the x-axis. Thus, all dicing cuts 1202 may be oriented parallel to each other. In this manner, composite wafer 1200 may be divided into transducers for a one-dimensional ultrasound probe configured for two-dimensional imaging.

[0069] The dicing cut 1202 separates a portion of the composite wafer 1200 into a plurality of transducer elements 1206, such as a first transducer element 1208 and a second transducer element 1210. Each of the transducer elements 1206 may include a portion of an impedance dematching layer 1212 stacked on top of a portion of a piezoelectric layer and a portion of an impedance matching layer with respect to the z-axis. The dicing cut 1202 may separate the transducer element 1206 from adjacent transducer elements and from a ground restoration region, such as a first ground restoration region 1214. In the illustrated example, each of the transducer elements 1206 may have a rectangular cross-section parallel to the xy plane.

[0070] Fig.14 FIG. 1 shows a transducer 1400 that may be used in a one-dimensional ultrasound probe configured for two-dimensional imaging. The transducer 1400 may be a transducer 1400 configured for two-dimensional imaging. Fig.12 The transducer 1400 includes a vertical dicing cut 1402 and may include an impedance dematching layer, a piezoelectric layer, and an impedance matching layer stacked along the z-axis.

[0071] The vertical dicing cut 1402 is parallel to the x-axis and extends completely across the transducer 1400 relative to the x-axis. In addition, the vertical dicing cut 1402 may be Figure 2 1400 and thus can separate adjacent transducer elements 1403 of the transducer 1400. The vertical dicing cuts 1402 can extend only partially into the transducer 1400 relative to the z-axis such that the vertical dicing cuts do not extend completely through the impedance matching layer of the transducer.

[0072] In the illustrated example, the transducer 1400 includes a first end region 1404 and a second end region 1406, wherein the second end region is positioned opposite the first end region relative to the y-axis. In addition, the transducer 1400 includes a central region 1408, wherein the central region is positioned in the middle of the first end region 1404 and the second end region 1406. The central region 1408 includes a vertical dicing cut 1402, while the vertical dicing cut may be omitted from the first end region 1404 and the second end region 1406. Therefore, the central region 1408 may include the transducer elements 1403 of the transducer 1400, while the first end region 1404 and the second end region 1406 may not include the transducer elements.

[0073] First ground restoration region 1410 is positioned in first end region 1404, and second ground restoration region 1412 is positioned in second end region 1406. First ground restoration region 1410 and second ground restoration region 1412 may facilitate ground restoration of transducer 1400. For example, ground restoration may be achieved through electrical communication between a continuous layer of transducer 1400 (e.g., a layer through which vertical dicing cut 804 does not extend completely) and first ground restoration region 1410 and / or second ground restoration region 1412. Furthermore, when transducer 1400 is included in a transducer assembly, first ground restoration region 1410 and second ground restoration region 1412 may be coupled to a flexible circuit (e.g., Figure 7 The flexible circuit 702 is electrically connected.

[0074] Fig.15 A one-dimensional transducer 1500 configured with an increased imaging footprint parallel to the y-axis is illustrated. The transducer 1500 may be a transducer separated from a composite wafer by a dicing cut oriented parallel to a single direction. The transducer 1500 includes a first end region 1502 and a second end region 1504, wherein the second end region is positioned opposite the first end region relative to the y-axis. In addition, the transducer 1500 includes a first ground restoration region 1506 positioned within the first end region 1502 and a second ground restoration region 1508 positioned within the second end region 1504. A central section 1510 of the transducer 1500 includes a plurality of dicing cuts 1512, and each of the dicing cuts separates a transducer element 1514 from an adjacent transducer element. Transducer elements 1514 extend completely across transducer 1500 relative to the y-axis, which can increase the imaging footprint of the transducer along the y-axis relative to a transducer having transducer elements that do not extend across the transducer relative to the y-axis. Fig.14 The transducer 1400 may have a larger imaging footprint relative to the x-axis, while Fig.15 The transducer 1500 may have a larger imaging footprint relative to the y-axis.

[0075] Fig. 9 A method 900 for manufacturing a one-dimensional transducer assembly (e.g., a probe) is illustrated. The one-dimensional transducer assembly may include a transducer and a flexible circuit, and a two-dimensional image may be generated. The transducer may include a piezoelectric layer, an impedance matching layer, and an impedance dematching layer stacked along a first axis. In addition, the edge of the transducer may extend along a second axis and a third axis, wherein the first axis, the second axis, and the third axis are orthogonal to each other. Therefore, the transducer may have a rectangular cross-section parallel to a plane formed by the second axis and the third axis. In some examples, the flexible circuit may be a printed circuit board (PCB).

[0076] At 902, method 900 includes dicing the composite wafer through the impedance dematching layer and the piezoelectric layer along a single direction. The composite wafer may include a piezoelectric layer, an impedance matching layer, and an impedance dematching layer stacked along a first axis. The piezoelectric layer may be positioned between at least a portion of the impedance matching layer and at least a portion of the impedance dematching layer relative to the first axis. In addition, the piezoelectric layer may include one or more portions of piezoelectric material positioned between portions of a grounded conductive material relative to a second axis or a third axis. In some examples, dicing of the wafer may be performed using a standard dicing saw or via laser dicing. In other examples, deep reactive ion or other semiconductor type etching may be used with an intermediate masking step. As a result of dicing, multiple dicing cuts may be introduced into the composite wafer.

[0077] The dicing cut may extend into the composite wafer along the first axis. In addition, the dicing cut may extend across the entire composite wafer parallel to one of the second axis or the third axis. For example, Fig.12 The dicing cut 1202 extends completely across the composite wafer 1200 relative to the x-axis. Thus, the dicing cut divides the wafer into a plurality of transducer elements and may separate adjacent transducer elements. The transducer elements may have a rectangular cross-section parallel to a plane formed by the second axis and the third axis. In some examples, the wafer may be diced into hundreds or thousands of transducer elements.

[0078] The composite wafer may be diced starting from the impedance matching layer of the wafer. Thus, the dicing cut may first be introduced into the impedance matching layer and may extend completely through the impedance matching layer relative to the first axis. In addition, the dicing cut may be introduced into the piezoelectric layer and may extend completely through the piezoelectric layer relative to the first axis. Thus, the dicing cut may extend deep enough to separate adjacent transducer elements from each other, wherein each transducer element includes a portion of the piezoelectric layer stacked on top of a portion of the impedance matching layer. In some examples, the dicing cut may then be introduced into the impedance matching layer, but may only partially extend through the impedance matching layer. Thus, the impedance matching layer may provide a common (e.g., continuous) mechanical support for the transducer elements. In addition, the impedance matching layer may include a conductive material for grounding recovery of the transducer elements. Thus, after dicing, the conductive film and / or conductive layer may not be deposited onto the composite wafer, thereby reducing the number of manufacturing steps (e.g., manufacturing complexity).

[0079] At 904, method 900 includes separating the transducer from the diced composite wafer. The composite wafer may include a plurality of transducers, wherein each transducer includes a plurality of transducer elements. The transducer element of each transducer may be separated from adjacent transducer elements by a dicing cut introduced into the composite wafer during dicing. In some examples, the transducer may be removed from the composite wafer via cutting (e.g., via a saw, a laser, etc.) and separated from the remainder of the composite wafer. The separated transducer includes a piezoelectric layer, an impedance matching layer, and an impedance dematching layer, and a plurality of transducer elements separated by the dicing cut.

[0080] At 906, method 900 includes coupling the transducer to the flexible circuit. The transducer and the flexible circuit are coupled together to form a transducer assembly (e.g., a probe), wherein the flexible circuit can ground the transducer and receive signals generated by the transducer. When coupled together, the impedance dematching layer of the transducer can make surface-sharing contact with one or more surfaces of the flexible circuit.

[0081] Coupling the transducer to the flexible circuit includes aligning the transducer elements of the transducer with the contact pads of the flexible circuit at 908. Alignment of each transducer element with the contact pads can be facilitated by pick-and-place equipment. As a result, the electrical connection (e.g., routing of signals) between the transducer and the flexible circuit can be more reliable. Coupling the transducer to the flexible circuit includes bonding the transducer elements to the contact pads at 910. In some examples, the transducer elements can be bonded to the contact pads via epoxy (e.g., glue), anisotropic conductive particles (ACP), or anisotropic conductive film (ACF).

[0082] At 912, method 900 optionally includes dicing the transducer through the impedance matching layer. In some examples, the directivity of the transducer assembly can be increased by dicing the transducer a second time, wherein the second set of dicing cuts are first introduced into the impedance matching layer of the transducer. Thus, the second set of dicing cuts can extend into the transducer in a direction parallel to the first axis and opposite to the direction in which the first set of dicing cuts extend into the transducer. In some examples, the second set of dicing cuts can extend completely through the impedance matching layer. Thus, a conductive film or layer can be deposited on the transducer assembly for electrical communication of grounding and transducer signals. In other examples, the second set of dicing cuts can extend only partially through the impedance matching layer. The second set of dicing cuts can reduce acoustic crosstalk between adjacent transducer elements.

[0083] Fig.10A method 1000 for manufacturing a two-dimensional transducer assembly (e.g., a probe) is illustrated. The two-dimensional transducer assembly may include a transducer and a flexible circuit, and a three-dimensional image (e.g., a volume image) may be generated. The transducer may include a piezoelectric layer, an impedance matching layer, and an impedance dematching layer stacked along a first axis. In addition, the edge of the transducer may extend along a second axis and a third axis, wherein the first axis, the second axis, and the third axis are orthogonal to each other. Therefore, the transducer may have a rectangular cross-section parallel to a plane formed by the second axis and the third axis. In some examples, the flexible circuit may be a printed circuit board (PCB).

[0084] At 1002, method 1000 includes dicing a composite wafer through an impedance matching layer and a piezoelectric layer along two orthogonal directions. The composite wafer may include a piezoelectric layer, an impedance matching layer, and an impedance matching layer stacked along a first axis. The piezoelectric layer may be positioned between at least a portion of the impedance matching layer and at least a portion of the impedance matching layer relative to the first axis, such as Figure 5 In addition, the piezoelectric layer may include one or more portions of piezoelectric material positioned between portions of the conductive grounding material relative to the second axis or the third axis, such as Fig.11 As shown. In some examples, dicing of the wafer may be performed using a standard dicing saw or via laser dicing. In other examples, deep reactive ion or other semiconductor type etching may be used with an intermediate masking step. As a result of dicing, multiple dicing cuts may be introduced into the composite wafer.

[0085] The dicing cuts may extend into the composite wafer along a direction parallel to the first axis. In addition, a first set of dicing cuts may be oriented along a first direction and a second set of dicing cuts may be oriented along a second direction, wherein the two directions are orthogonal to each other and to the first axis. For example, Figure 2 The first set of dicing cuts 208 and the second set of dicing cuts 208 may be orthogonal and extend completely across the composite wafer 200 relative to the x-direction and the y-direction, respectively. In some examples, the first set of dicing cuts may be oriented parallel to the second axis, and the second set of dicing cuts may be oriented parallel to the third axis. In addition, the dicing cuts may extend across the entire composite wafer parallel to the second axis and the third axis. Thus, the dicing cuts divide the composite wafer into a plurality of transducer elements and may separate adjacent transducer elements. The transducer element may have a rectangular cross-section parallel to the plane formed by the second axis and the third axis. In some examples, the wafer may be diced into hundreds or thousands of transducer elements.

[0086] The composite wafer may be diced starting from the impedance matching layer of the wafer. Thus, the dicing cut may first be introduced into the impedance matching layer and may extend completely through the impedance matching layer relative to the first axis. In addition, the dicing cut may be introduced into the piezoelectric layer and may extend completely through the piezoelectric layer relative to the first axis. Thus, the dicing cut may extend deep enough to separate adjacent transducer elements from each other, wherein each transducer element includes a portion of the piezoelectric layer stacked on top of a portion of the impedance matching layer and in contact with the impedance matching layer. In some examples, the dicing cut may then be introduced into the impedance matching layer, but may only partially extend through the impedance matching layer. Thus, the impedance matching layer may provide a common (e.g., continuous) mechanical support for the transducer elements. In addition, the impedance matching layer may include a conductive material for grounding recovery of the transducer elements. Thus, after dicing, the conductive film and / or conductive layer may not be deposited on the composite wafer, thereby reducing the number of manufacturing steps (e.g., manufacturing complexity).

[0087] At 1004, method 1000 includes separating the transducer from the diced composite wafer. At 1006, method 1000 includes coupling the transducer to a flexible circuit. Coupling the transducer to the flexible circuit includes aligning a transducer element of the transducer with a contact pad of the flexible circuit at 1008. Additionally, coupling the transducer to the flexible circuit includes bonding the transducer element to the contact pad at 1010. At 1012, method 1000 optionally includes dicing the transducer through an impedance matching layer. 1004, 1006, 1008, 1010, and 1012 may be respectively Fig. 9 904, 906, 908, 910 and 912 are the same. It should be understood that for a transducer lacking an impedance matching layer (e.g., Fig.16 Transducer 1601), methods 900 and 1000 may be performed as described above, but the dicing of the composite wafer begins with the piezoelectric layer and the resulting transducer is coupled to the flexible circuit such that the piezoelectric layer is coupled to the flexible circuit rather than the impedance dematching layer.

[0088] The present disclosure also provides support for a transducer assembly, the transducer comprising: a flexible circuit; and a transducer, the transducer comprising a piezoelectric layer and an impedance matching layer, wherein the transducer comprises a plurality of transducer elements, the plurality of transducer elements being formed via a plurality of dicing cuts positioned between adjacent transducer elements of the plurality of transducer elements, and each of the plurality of dicing cuts extending only partially through the impedance matching layer. In a first example of the assembly, the assembly further comprises: an impedance dematching layer, wherein the impedance dematching layer makes surface-sharing contact with one or more surfaces of the flexible circuit. In a second example of the assembly, optionally including the first example, each of the plurality of dicing cuts extends completely through at least a portion of the piezoelectric layer and the impedance dematching layer. In a third example of the assembly, optionally including one or both of the first and second examples, the plurality of transducer elements are bonded to contact pads of the flexible circuit. In a fourth example of the assembly, optionally including one or more or each of the first to third examples, the plurality of transducer elements are bonded to the contact pad via epoxy. In a fifth example of the assembly, optionally including one or more or each of the first to fourth examples, the plurality of dicing cuts include a first group of dicing cuts parallel to a first axis and a second group of dicing cuts parallel to a second axis, wherein the second axis is orthogonal to the first axis. In a sixth example of the assembly, optionally including one or more or each of the first to fifth examples, the piezoelectric layer is in surface-sharing contact with one or more surfaces of the flexible circuit, and wherein each of the plurality of dicing cuts extends completely through the piezoelectric layer. In a seventh example of the assembly, optionally including one or more or each of the first to sixth examples, at least a portion of the impedance matching layer is continuous from the first end of the transducer to the second end of the transducer. In an eighth example of the component, optionally including one or more or each of the first to seventh examples, the impedance matching layer includes a conductive material. In a ninth example of the component, optionally including one or more or each of the first to eighth examples, the impedance matching layer includes a first sublayer and a second sublayer, wherein at least a portion of the first sublayer is positioned between the second sublayer and the piezoelectric layer. In a tenth example of the component, optionally including one or more or each of the first to ninth examples, the system further includes: a first ground recovery area at a first side of the transducer and a second ground recovery area at a second side of the transducer. In an eleventh example of the component, optionally including one or more or each of the first to tenth examples, each of the first ground recovery area and the second ground recovery area is aligned with a corresponding ground signal connection of the flexible circuit.

[0089] The present disclosure also provides support for a method for manufacturing a transducer assembly, the method comprising: dicing a transducer to form a dicing cut that separates a transducer element from an adjacent transducer element; aligning the transducer element with a contact pad of a flexible circuit; and bonding the transducer to the flexible circuit. In a first example of the method, dicing the transducer includes dicing the transducer through an impedance dematching layer and a piezoelectric layer of the transducer such that the dicing cut extends completely through the impedance dematching layer and the piezoelectric layer of the transducer relative to a first axis. In a second example of the method, optionally including the first example, dicing the transducer includes dicing the transducer partially through an impedance matching layer of the transducer such that the dicing cut extends only partially into the impedance matching layer relative to the first axis. In a third example of the method, optionally including one or both of the first and second examples, aligning the transducer element with a contact pad of the flexible circuit includes aligning the transducer element with the contact pad via pick-and-place equipment. In a fourth example of the method, optionally including one or more or each of the first to third examples, the method further includes: dicing one or more additional transducers together with the transducer and separating the transducer from the one or more additional transducers. In a fifth example of the method, optionally including one or more or each of the first to fourth examples, dicing the transducer includes dicing the transducer so that a first set of diced cuts are oriented parallel to a second axis, and dicing the transducer so that a second set of diced cuts are oriented parallel to a third axis, wherein the second axis and the third axis are orthogonal to each other.

[0090] The present disclosure also provides support for a transducer system, the transducer system comprising: a transducer, the transducer comprising a piezoelectric layer, an impedance matching layer, a first conductive end segment, and a second conductive end segment, wherein the piezoelectric layer is positioned intermediate the first conductive end segment and the second conductive end segment; and a flexible circuit, wherein a bottom surface of the transducer is directly coupled to a contact pad of the flexible circuit. In a first example of the system, the transducer comprises a diced cut extending completely through the piezoelectric layer and partially through the impedance matching layer, wherein at least a portion of the impedance matching layer is continuous, and wherein the bottom surface comprises a bottom surface of the piezoelectric layer or a bottom surface of an impedance dematching layer.

[0091] The technical effect of the transducer assembly manufacturing process including dicing completely through the impedance dematching layer and the piezoelectric layer and dicing not completely through the impedance matching layer is that dicing can be performed collectively at the wafer level, rather than individually at the circuit level. In addition, at least a portion of the impedance matching layer remains continuous, thereby providing mechanical stability and ground restoration without the need to bond an additional conductive layer to the transducer assembly.

[0092] Figures 1 to 8and Figures 11 to 16 An example configuration with relative positioning of various parts is shown. In at least one example, if shown as being in direct contact or directly coupled to each other, such elements may be referred to as being in direct contact or directly coupled, respectively. Similarly, in at least one example, elements shown as being adjacent or adjacent to each other may be adjacent or adjacent to each other, respectively. For example, parts placed in coplanar contact with each other may be referred to as being in coplanar contact. For another example, in at least one example, elements positioned to be spaced apart from each other and having only space therebetween without other parts may be described and referenced as such. For another example, elements shown as being located above / below / below each other, located on opposite sides or located between the left / right sides of each other may be described and referenced as such relative to each other. In addition, as shown in the figure, in at least one example, the topmost element or the point of the element may be referred to as the "top" of the part, and the bottommost element or the point of the element may be referred to as the "bottom" of the part. As used herein, top / bottom, upper / lower, upper / lower may be relative to the vertical axis of the figure, and may be used to describe the position of the elements relative to each other in the figure. Thus, in one example, elements shown as being above other elements are positioned vertically above other elements. For another example, the shapes of the elements depicted in the figures may be referred to as having those shapes (e.g., such as being round, straight, planar, curved, rounded, chamfered, angled, etc.). In addition, in at least one example, elements shown as intersecting each other may be referred to as intersecting elements or intersecting each other. In addition, in one example, elements shown as being within another element or being shown as being outside another element may be described and referenced as such.

[0093] As used herein, the elements or steps listed in the singular and beginning with the word "one" or "a kind of" should be understood as not excluding a plurality of said elements or steps, unless such exclusion is explicitly stated. In addition, the reference to "one embodiment" of the present invention is not intended to be interpreted as excluding the existence of additional embodiments that also include the cited features. In addition, unless explicitly stated to the contrary, "comprising", "including" or "having" an embodiment of an element or multiple elements with a specific characteristic may include additional such elements that do not have the characteristic. The terms "including" and "in..." are used as the concise language equivalents of the corresponding terms "including" and "wherein". In addition, the terms "first", "second" and "third" etc. are only used as marks, and are not intended to impose numerical requirements or specific positional order on their objects.

[0094] This written description uses examples to disclose the invention, including the best mode, and also to enable a person skilled in the relevant art to practice the invention, including making and using any devices or systems and performing any included methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to a person skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insignificant differences from the literal language of the claims.

Claims

1. A transducer assembly (700, 1600), comprising: Flexible circuit (702); and A transducer (600), comprising a piezoelectric layer (502) and an impedance matching layer (505); wherein the transducer (600) comprises a plurality of transducer elements (602), the plurality of transducer elements being formed via a plurality of dicing cuts (608) positioned between adjacent transducer elements of the plurality of transducer elements (602); and Each of the plurality of dicing cuts (608) extends only partially through the impedance matching layer (505).

2. The transducer assembly (700) of claim 1, further comprising an impedance dematching layer (508), wherein the impedance dematching layer (508) makes surface-sharing contact with one or more surfaces of the flexible circuit (702).

3. The transducer assembly (700) of claim 2, wherein each of the plurality of diced cuts (608) extends completely through the piezoelectric layer (502) and at least a portion of the impedance dematching layer (508).

4. The transducer assembly (700, 1600) of claim 1, wherein the plurality of transducer elements (602) are bonded to contact pads of the flexible circuit (702).

5. The transducer assembly (700, 1600) of claim 1, wherein the plurality of dicing cuts (608) include a first set of dicing cuts parallel to a first axis and a second set of dicing cuts parallel to a second axis, wherein the second axis is orthogonal to the first axis.

6. The transducer assembly (700, 1600) of claim 1, wherein the piezoelectric layer (1602) is in surface-sharing contact with one or more surfaces of the flexible circuit (702), and wherein each of the plurality of dicing cuts (1608) extends completely through the piezoelectric layer (1602).

7. The transducer assembly (700, 1600) of claim 1, wherein at least a portion (506) of the impedance matching layer (505) is continuous from a first end of the transducer to a second end of the transducer, and wherein the impedance matching layer (505) comprises a conductive material.

8. The transducer assembly (700, 1600) of claim 1, wherein the impedance matching layer (505) comprises a first sublayer (504) and a second sublayer (506), wherein at least a portion of the first sublayer (504) is positioned between the second sublayer (506) and the piezoelectric layer (502).

9. The transducer assembly (700, 1600) of claim 1, further comprising a first ground restoration area (510) at a first side of the transducer and a second ground restoration area (512) at a second side of the transducer, wherein each of the first ground restoration area (510) and the second ground restoration area (512) are aligned with a corresponding ground signal connection (704, 706) of the flexible circuit (702).

10. A method (900, 1000) for manufacturing a transducer assembly, the method comprising: dicing the transducer (902, 1002) to form dicing cuts separating the transducer element from an adjacent transducer element; aligning the transducer element with contact pads of a flexible circuit (908, 1008); and The transducer is coupled (910, 1010) to the flexible circuit.

11. The method (900, 1000) of claim 10, wherein dicing the transducer (902, 1002) comprises dicing the transducer through an impedance dematching layer and a piezoelectric layer of the transducer such that the dicing cut extends completely through the impedance dematching layer and the piezoelectric layer of the transducer relative to a first axis.

12. The method (900, 1000) of claim 10, wherein dicing the transducer (902, 1002) comprises dicing the transducer partially through an impedance matching layer of the transducer such that the diced cut extends only partially into the impedance matching layer relative to a first axis.

13. The method (900, 1000) of claim 10, wherein aligning (908, 1008) the transducer element with a contact pad of the flexible circuit comprises aligning the transducer element with the contact pad via pick and place equipment.

14. The method (900, 1000) of claim 10, further comprising dicing one or more additional transducers together with the transducer and separating the transducer from the one or more additional transducers (904, 1004).

15. The method (1000) of claim 10, wherein dicing the transducer (1002) comprises dicing the transducer such that a first set of dicing cuts are oriented parallel to a second axis, and dicing the transducer such that a second set of dicing cuts are oriented parallel to a third axis, wherein the second axis and the third axis are orthogonal to each other.

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